#include<stdio.h>
int main()
{
	int n;
	double sum,fact;
	scanf("%d",&n);
	sum=0;
	fact=1;
	for(int i = 1;i <= n;i++) {
		fact = fact*i;
		sum += fact;
		if(sum>=n) {
     	printf("m<=%d\n",i-1);
	break;
}
	}
	return 0;
}
